mml=<math xmlns="http://www.w3.org/1998/Math/MathML"><mstyle mathsize="12px"><mrow><mi mathvariant="normal">x</mi><mo> </mo><mo>=</mo><mo> </mo><mi>nπ</mi><mo> </mo><mo>+</mo><mo> </mo><msup><mi>cos</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup><mo> </mo><mo>(</mo><mn>1</mn><mo>/</mo><mn>3</mn><mo>)</mo></mrow></mstyle></math>